Apron loader for a scraper

ABSTRACT

A scraper including a tractor and trailing bowl in which the latter is provided with an apron the upper end of which is connected with a pivoted control arm which guides the apron as the lower edge thereof is rotated by a drive crank so as to assist loading material into the bowl during a digging operation.

United States Patent Inventor William ll. Eiger Eastlake, Ohio July 15, 1969 Mar. 23, 1971 General Motors Corporation Detroit, Mich.

Continuation-impart of application Ser. No. 644,128, June 7, 1967, now abandoned.

Appl. No. Filed Patented Assignee APRON LOADER FOR A SCRAPER 2 Claims, 6 Drawing Figs. US. Cl 37/4, 37/129, 37/126 Int. Cl .I B60p l/00 Field of Search 37/4, 126, 126 (NN5), 129, 129 (G), 129 (H), 124, 125, (PL Digest); 198/10 [56] References Cited UNITED STATES PATENTS 1,903,675 4/ 1933 l-lauge 198/10 2,396,287 3/1946 Robb 37/4UX 2,844,892 7/ 1958 Carston 37/4 3,067,888 12/ 1962 Reynolds... 37/126 3,105,311 10/1963 Hait 37/4 3,221,424 12/ 1 965 Hancock 37/4UX 3,351,002 1 H1967 McDuffie 198/10 3,360,110 12/1967 -Ederet a1. 198/10 Primary Examiner-Edgar S. Burr Attorneys-.1. L. Carpenter and E. .l. Biskup ABSTRACT: A scraper including a tractor and trailing bowl in which the latter is provided with an apron the upper end of which is connected with a pivoted control arm which guides the apron as the lower edge thereof is rotated by a drive crank so as to assist loading material into the bowl during a digging operation.

PATENTEDHAR23|97| 3,671,955 sum 1 o s ATTORNEY PA-TE'NTEDMAR 2 l97| 3,571. 955 Sam 2 or 3 IINVEN'TOR.

ATTORNEY PATENTEUmzmQn' $571,955

snmaurs ATTORNEY APRON LOADERFOR A SCRAPER This application is a continuation-in-part of my copending application U.S. Ser. No. 644,128, filed on Jun. 7, 1967, now abandoned, entitled "Apron Loader for a Scraper" and assigned to the assignee of this invention.

In the past, various forms of self-loading scrapers have been proposed in which the apronis utilized as the loading implement. In almost all cases, however, the apron operating mechanism is such that movement of the apron is restricted to a straight line or arcuate path with vertical height adjustment being provided through a control mechanism supported by the pull yoke and connected to the front of the apron. Asshould be apparent, an arrangement of this sort requires the constant attention of the operator to make certain that the apron is at the proper height relative to the cutting blade so that upon rearward movement of the apron, optimum loading of material into the bowl is attained. This task is further complicated by the fact that the apron, having the form of a solid wall and being located between the operator and the cutting edge, serves to obstruct a clear view of conditions existing at the cutting edge. Hence, at times, it may not be apparent to the operator whether the apron should be actuated for assisting loading of the bowl. a

Accordingly, the principal objects of this invention are to provide a scraper having an apron that assists loading of a scraper bowl without requiring any special attention from the vehicle operator; to provide a scraper having an apron that is driven fore and aft of the cutting edge in a fixed circular path during a loading operation so as to cause material at the cutting blade to be pushed toward the rear of the bowl and thereby reduce the power requirements of the prime mover; to provide a self-loading scraper bowl in which the lower edge of the apron is supported for movement along an elliptical path having its major axis extending longitudinally of the bowl; to provide an orbiting apron which facilitates loading of th scraper bowl by pushing the material atthe cutting blade rearwardly and upwardly into the bowl; to provide a loader for the front end of a scraper bowl that assists loading of cut material into the bowl and includes an orbiting apron the lower edge of which is driven in an elliptical path that can vary in height relative to the cutting blade during'a loading operation; and to provide an apron-type loader for a scraper bowl that includes a drive system which is supported by a pivoted arm whereby the distance between the lower edge of the apron and the cutting blade of the scraper bowl can be adjusted.

In the preferred form the scraper made according to the invention includes a tractor and a trailing bowl, the latter of which has a pair of upstanding sidewalls 43 and a transversely extending cutting blade. An apron extends between the sidewalls and has a position wherein the lower edge of the apron is located adjacent the cutting blade so as to close the front of the bowl. A pair of laterally spaced control arms each have one end thereof pivotally connected to the bowl, while the other end is pivotally connected to the apron at an upper point thereof. Drive means in the form of a hydraulic motor and suitable gearing are carried by the bowl and include a drive shaft supporting a crank which is pivotally connected to the apron adjacent the lower edge thereof. When the drive means is activated, the crank rotates .about a transverse horizontal axis and the apron is driven through an orbital path with the lower edge of the apron continuously changing its angularity relative to a vertical plane passing through the center axis of the drive shaft. The drive means is normally activated during a digging operation so as to facilitate loading of the scraper bowl by pushing the material at the cutting blade rearwardly and upwardly into the bowl.

The above objects and others will be more apparent to the reader upon review of the following detailed description when taken in conjunction with the drawings in which:

FIG. 1 is an elevation view of a scraper incorporating an apron made in accordance with the present invention;

FIG. 2 is a plan view of the scraper of FIG. 1;

FIG. 3 is an enlarged view showing the apron in two positions as it is driven by the associated operating mechanism;

other positions;

FIG. 4 is a view similar to FIG. 3 but shows the apron in two FIG. 5 is a view of the apron loader similar to FIG. 3 but includes a modification which allows the apron to he udjustuhly positioned relative to the cutting blade; and

FIG. 6 is a plan view of the scraper bowl shown in FIG. 5.

Referring to the drawings and more particularly FIGS. l and 2 thereof, a self-propelled rubber-tired scraper is shown comprising an overhung tractor 10 connected by way of a draft frame 12 to a trailing bowl 14. The tractor l0 is provided at its forward end with the usual engine, not shown. and operator station 16, while the rear end thereof includes an upstanding pivotpost 18 which is hingedly connected to a rearwardly extending gooseneck 20 which forms a part of the draft frame l2. The hinged connection between the draft frame and the tractor provides for relative articulation of the units in the usual manner for steering purposes. The gooseneek 20 extends rearwardly for rigid connection with a transversely extending torque tube 22, the opposite ends of which are provided with pull arms 24 and 26 which are respectively pivotally connected to upstanding sidewalls 28 and 30 of the bowl l4 and support the latter for movement between a raised-carry position and a lowered-dig position. A pair of hydraulic jacks 32 and 34 have their upper ends pivotally connected to the torque tube 22 while their lower ends are pivotally connected to the frontend of the sidewalls 28 and 30 of the bowl so to provide, for movement of the latter between the aforementioned positions.

Extending between the sidewalls 28 and 30 of the bowl I4 is an ejector 36 having a flat floor portion 38 which leads into an integrally formed and upstanding back wall 40. The forward end of the ejector 36 is hingedly connected with a transversely extending cutting blade 42 while the rear end of the ejector 36 is connected with an ejector actuating mechanism including line 44. lever 46. and hydraulic jacks 48. all of which cooperate for raising the back wall 40 of the ejector 36 for wardly while simultaneously moving the forward end of the ejector 36 including the cutting blade 42 rearwardly along a longitudinally extending guide track so as to dump the load from the bottom of the bowl l4. An ejection system similar to this type can be seen in US. Pat. No. 3,057.090jn the name of Janis Mazzarins, and assigned to the assignee of this invention, and therefore, reference is made thereto for further detailed description of this form of device. 7

The front of the bowl I4 is provided with an apron 52 and associated operating mechanism for facilitating loading of the bowl during a digging operation. The apron 52 is generally of conventional design and consists of an arcuate transversely extending plate which, when in the'position of FIG. I, serves to close the mouth of the bowl l4 and thereby retain material therein. The upper end of the apron 52 is supported by laterally spaced control arms 54 and 56 located at the opposite sides of the apron and pivotally connected thereto at transversely aligned points 58 and 60. The respective control arms 54 and 56 extend rearwardly for pivotal connection at axially aligned points 62 and 64 with the sidewalls of the bowl l4 and serve as guide arms for maintaining the upper portion of the apron 52 in predetermined positions as the latter moves in an orbital path while being driven by mechanism to be now described.

In this connection, it will be noted that the forward end of each sidewall rotatably supports a gear wheel 66which is connected by a chain 68 to end gears mounted on a drive shaft 70 which, in turn, is powered through a suitable gearing arrangement 72 by a hydraulic motor 74 supported by a beam 75 at- FIGS. 3 and 4 of the drawings are fragmentary views of the bowl [4 taken on a vertical section and illustrate the movement of the apron 52 while being driven by the gear mechanism described above. For example, as shown in FIG. 3, the gear wheel 66 is driven in a counterclockwise direction so that the crank 76 is rotated from the six o'clock to the three o'clock position and causes the apron 52 to be raised upwardly and rearwardly with the lower edge thereof following an arcuate path. lnasmuch as the rear of the control arm 54 is pivotally connected to the wall 30, it serves as a guide for controlling movement of the upper end of the apron 52 while the lower portion of the latter is being driven by the crank 76. HO. 4 shows the positions of the apron 52 as the crank 76 continues its rotation from the twelve o'clock to the nine o'- clock position whereafter the crank 76 then assumes the six o'clock position of FIG. 3. It will be noted that as the apron 52 is rotated through one complete cycle, the lower edge of the apron follows a circular path 80 which is of an elliptical form with the major axis thereof extending longitudinally of the bowl 14 and substantially parallel to the floor portion 38 of the ejector 36.

In operation, the scraper will normally enter the cut with the apron 52 positioned somewhat as shown in phantom lines of P16. 4. The bowl 14 will then be lowered by operation of the jacks 32 and 34 to the desired depth of cut and be propelled forwardly the the tractor 10. Loading in this manner can be continued without operation of the apron mechanism, however, as soon as it is noticed that the scraper-is experiencing difficulty in loading, the operator may energize the hydraulic motor 74 and cause the apron 52 to be driven in the aforementioned manner resulting in dirt located adjacent the cutting blade 42 being propelled rearwardly into the bowl 14.

F108. 5 and 6 disclose a modification of the invention shown in FlGS. 14 that differs therefrom basically in that a pair of laterally spaced support arms 100 and 102 are provided for carrying the apron loader and moving it as a unit relative to the bowl 14'. Accordingly, it will be noted that all parts of the modified form of the invention which correspond to those parts incorporated with the invention as seen in FIGS. 1-4 will be identified by the same numerals but primed.

With reference to F105. 5 and 6, it will be noted that the rear ends of the support arms 100 and 102 are respectively pivotally connected to the sidewalls 28' and 30' of the bowl 14 at the pivot points 62 and 64' which also serve as the pivot points for the control arms 54 and 56, the forward ends of which are pivotally connected to the upper end of the apron 52 at point 58'. The drive means, which includes the gear wheel 66' connected by chain 68' to the gearing arrangement 72 as well as the hydraulic motor 74', is carried at the forward end of the support arm 102. The drive shaft 70 extends transversely of the bowl 14' to drive an identical gearing arrangement supported on the opposite side of the bowl by the support arm 100. By mounting all of the drive means on the support arms 100 and 102 rather than on the sidewalls of the bowl as in the case of the invention as shown in FIGS. 1-4, the apron loader enjoys increased versatility in that the level of the circular path 80 (FIG. 3) followed by the lower edge of the apron 52' can be adjustably varied relative to the cutting blade 42'. In this regard, it will be noted that the rear end of each support arm 100 and 102 is formed with a rigid lug 104 having an offset portion which passes through a curved slot 106 formed in the associated sidewall of the bowl 14. The lower end of the lug 104 is connected by a pivotal connection 107 to the piston rod end of a double-acting hydraulic cylinder 108, the cylinder end of which is pivotally mounted to the outside of the associated sidewall of the bowl 14. Thus, by expanding the hydraulic cylinders 108, the support arms 100 and 102 together with the supported apron and drive arrangement can be raised to various elevations relative to the cutting blade 42'.

Under certain circumstances, it may be found advantageous to permit the support arms and 102, and accordingly the a ron 52, to float durin a loading e do. To aceom lish this, I e control valve which orms a part ol the hydrau re circuit for supplying pressurized fluid to the hydraulic cylinders 108, can be placed in a float position so as to permit the support arms to be freely movable about the pivot points 62' and 64 during the loading operation. Under such conditions. the apron loader will tend to seek the most favorable elevation for loading the material from the cutting blade 42 into the bowl 14. It will be appreciated that although not shown an interconnecting strut can be provided for rigidly connecting the support arms 100 and 102 so as to assure concurrent movement of the support arms about their pivotal supports.

lelaim:

1. An earthmoving vehicle having a material retaining bowl provided with an open end and including a horizontal cutting blade extending transversely of the bowl and located in said open end, said bowl comprising a pair of laterally spaced sidewalls a back wall and a floor portion, an apron extending between said sidewalls to close the open end of the bowl and having an upper portion and a lower edge which is normally located adjacent the cutting blade, support arm means having a rear portion and a forward portion extending along said sidewalls, means pivotally connecting the rear portion of said support arm means to the said sidewalls along a first horizontal axis extendingtransvcrsely of the bowl, a drive mechanism including a hydraulic motor carried by said forward portion of the support arm means for orbiting the lower edge of the apron in a closed curved path whereby material cut by said cutting blade is moved rearwardly into the bowl, control arm means pivotally connected between the upper portion of the apron and a point on said sidewalls lying along said first horizontal axis for guiding movement of said upper portion of said apron while the lower edge of said apron is being orbited by said crank, and a pair of double acting hydraulic cylinders supported by the bowl and pivotally connected to the support arm means for raising the latter about said first horizontal axis whereby said closed curved path is adjustably positioned relative to said cutting blade.

2. An earthmoving vehicle having a material retaining bowl provided with an open end and including a horizontal cutting blade extending transversely of the bowl and located in said open end, said bowl comprising a pair of laterally spaced sidewalls, a back wall and a floor portion, an apron extending between said sidewalls to close the open end of the bowl and having an upper portion and a lower edge which is normally located adjacent the cutting blade, support arm means having a rear portion and a forward portion extending along said sidewalls, means pivotally connecting the rear portion of said support arm means to the sidewalls along a first horizontal axis extending transversely of the bowl, a drive mechanism carried by the forward portion of the support arm means for orbiting the lower edge of the apron in an elliptical path whereby material cut by said cutting blade is moved rearwardly into the bowl, said drive mechanism including a rotatable crank having one end thereof pivotally connected to said apron adjacent the lower edge thereof. control arm means pivotally connected between the upper portion of the apron and a point on said sidewalls lying along said first horizontal axis for guiding movement of said upper portion of said apron while the lower edge of said apron is being orbited by said crank, and hydraulic cylinder means supported by the bowl and connected to the support arm means for raising the latter about said first horizontal axis whereby said elliptical path is adjustably positioned relative to said cutting blade. 

1. An earthmoving vehicle having a material retaining bowl provided with an open end and including a horizontal cutting blade extending transversely of the bowl and located in said open end, said bowl comprising a pair of laterally spaced sidewalls a back wall and a floor portion, an apron extending between said sidewalls to close the open end of the bowl and having an upper portion and a lower edge which is normally located adjacent the cutting blade, support arm means having a rear portion and a forward portion extending along said sidewalls, means pivotally connecting the rear portion of said support arm means to the said sidewalls along a first horizontal axis extending transversely of the bowl, a drive mechanism including a hydraulic motor carried by said forward portion of the support arm means for orbiting the lower edge of the apron in a closed curved path whereby material cut by said cutting blade is moved rearwardly into the bowl, control arm means pivotally connected between the upper portion of the apron and a point on said sidewalls lying along said first horizontal axis for guiding movement of said upper portion of said apron while the lower edge of said apron is being orbited by said crank, and a paIr of double acting hydraulic cylinders supported by the bowl and pivotally connected to the support arm means for raising the latter about said first horizontal axis whereby said closed curved path is adjustably positioned relative to said cutting blade.
 2. An earthmoving vehicle having a material retaining bowl provided with an open end and including a horizontal cutting blade extending transversely of the bowl and located in said open end, said bowl comprising a pair of laterally spaced sidewalls, a back wall and a floor portion, an apron extending between said sidewalls to close the open end of the bowl and having an upper portion and a lower edge which is normally located adjacent the cutting blade, support arm means having a rear portion and a forward portion extending along said sidewalls, means pivotally connecting the rear portion of said support arm means to the sidewalls along a first horizontal axis extending transversely of the bowl, a drive mechanism carried by the forward portion of the support arm means for orbiting the lower edge of the apron in an elliptical path whereby material cut by said cutting blade is moved rearwardly into the bowl, said drive mechanism including a rotatable crank having one end thereof pivotally connected to said apron adjacent the lower edge thereof, control arm means pivotally connected between the upper portion of the apron and a point on said sidewalls lying along said first horizontal axis for guiding movement of said upper portion of said apron while the lower edge of said apron is being orbited by said crank, and hydraulic cylinder means supported by the bowl and connected to the support arm means for raising the latter about said first horizontal axis whereby said elliptical path is adjustably positioned relative to said cutting blade. 